I buy in bulk, not a pissy little jam jar full.
(when I let it out there is no half measures)

 

Well guys...this issue was finally fixed after I swapped out my spark plugs but more importantly...built an entirely new E.F.I harness from scratch.

Too much to describe in 1 quick post but here are the misadventures right here:

https://www.jaguarforums.com/forum/x...ss-h-e-171613/

Once I installed the new EFI harness she was purring like a cat. I ran some tests after some heatsoaking and she still didn't miss a beat.

Whilst I was at it, after she past the test, I upgrade my ECU from 6CU to 16CU.

Prognosis?

Hard to say exactly but my EFI harness had alot of broken insulation and corroded terminals. Maybe when the engine was heatsoaking after I had been sitting in traffic a while or similar, it caused high resistance and maybe not firing all injectors. I dunno...fixed now and I am one happy camper!

So in summary...

1) New water pump
2) Cold air intake mod
3) Repaired AAV thanks to the WoOz Grant Francis
4)Installed new spark plugs
5)Built new EFI harness.

After step 5 she came good!

Thanks for everybody's help!